Of course Aragorn is not the best human fighter in The Lord of the Rings. Boromir is.
And neither could beat Glorfindel, Elrond or Legolas, as they don’t have thousands of years of combat experience to draw upon.
Conan, though, is the champion, unless you put him against Lancelot du Lac or Elric of Melnibone.
The Ministry of Gentlemanly Warfare